The invention relates to a cooling arrangement for components disposed in an interior of a switch cabinet, having a switch cabinet and a cooling apparatus which has a first closed coolant circuit and a second coolant circuit separated fluidically therefrom, the first coolant circuit having a refrigerating machine or a cold water set and the second coolant circuit having a heat pipe arrangement or a two-phase thermosiphon. A cooling arrangement of this type is known from DE 102 96 928 T5. DE 690 05 701 T2, US 2003/0057546 A1 and US 2012/0103571 A1 likewise in each case describe a similar arrangement.
Such cooling apparatuses often comprise a refrigerating machine, in which a compressor, a condenser, an expansion means and an evaporator are arranged one behind the other in the coolant flow direction in a coolant circuit. The refrigerating machine is designed, in principle, for providing sufficient cooling of the switch cabinet interior under extreme conditions, that is to say at maximum ambient temperatures and at the same time maximum power dissipations of the components accommodated in the switch cabinet. However, since these extreme conditions are prevalent only in exceptional cases, the refrigerating machine is most of the time in on/off operation, that is to say in an energy-inefficient operating mode.
Furthermore, refrigerating machines have the disadvantage of having comparatively high energy consumption. It is therefore desirable, in principle, to provide at least a proportion of the required cooling capacity with the aid of alternative cooling techniques. For this purpose, cooling apparatuses are known from the prior art which combine an air/air heat exchanger with a refrigerating machine, so that, when there is a sufficiently large temperature difference between the switch cabinet desired temperature and the ambient air temperature of the switch cabinet, the required cooling capacity can be provided solely or at least as far as possible with the aid of the air/air heat exchanger. Such combined cooling apparatuses are also designated later on in the application as “hybrid cooling apparatuses”. Hybrid cooling apparatuses which have an air/air heat exchanger have the disadvantage that, in the event that the ambient air temperature lies above the switch cabinet temperature, heating of the switch cabinet would take place if warm ambient air were to continue to flow through the air/air heat exchanger, and therefore, in the cooling apparatuses known from the prior art, a complicated flat valve mechanism is provided for diverting the ambient air from the heat exchanger in the situation referred to. However, these mechanisms involve a high outlay and are complicated to handle.
In general, cooling circuits having a refrigerating machine or a cold water set which introduce cold into the system and serve as a rule for cooling a cooling medium are designated as “active” cooling circuits. The cold water set may in the simplest case have a cold water reservoir, and in this context a person skilled in the art will understand that “water” in cooling applications is not to be interpreted restrictively, but is used merely as a synonym for the coolants or refrigerants, generally designated as “cooling medium”, which are known from the prior art. Correspondingly, “passive” cooling circuits have no refrigerating machine and no cold water set. Active cooling of a cooling medium does not take place in these.